Field of the Invention
The present invention relates to an image forming device which can sequentially form images on sheets at a predetermined cycle, and an image forming method and an image forming system.
Description of the Related Art
In an image forming device such as a copier, a printer and a multifunction printer and an image forming system, printing is performed by forming a toner image on a photoreceptor provided at an image forming section based on image data obtained by, for example, being read from a document reading device, transferring the toner image to a sheet fed from a paper feed tray and fixing the toner image. Further, the sheet on which an image has been formed on the front side is conveyed by being reversed at a reverse conveying section if desired, and returned to a sheet conveying section, and thereby an image can be formed and fixed on the back side.
Because a sheet on which an image is formed but not fixed is conveyed to a fixer which makes a sheet pass through a fixing roller, a pressure belt, or the like, and fixes a toner image on the sheet by heating, pressure, or the like, there is a case where a fixing member such as the fixing roller and the pressing belt may be contaminated by a toner over time, or a toner may adhere to the fixing member by sheet jam. When a sheet is newly made to pass through such a fixer, the sheet is contaminated by the toner of the fixing member adhering to the sheet.
Further, there is a case where a position where an image is formed is displaced in both side printing or where image density may change over time. Such contamination, displacement and change in the image density become a defect of the image depending on the level and degrade printing quality. It is therefore necessary to visually check the output.
Further, there is a case where when operating time is accumulated, image adjustment is not favorably performed, which degrades image quality such as color stability.
However, when a large number of pages are printed or a large number of copies are made, if the printed results are tried to be visually checked, a huge amount of man-hours and cost is required, and, further, accuracy varies. Therefore, there is a proposed device which detects whether or not there is a defect in image data after the image data is transferred to a sheet. For example, Japanese Patent Laid-Open No. 2005-161650 proposes an image forming device which forms a pattern for color calibration on a sheet, visualizing the pattern to detect a characteristic amount and performing a color calibration process based on the detected characteristic amount.
However, in the proposed technique which is used in an adjustment mode, correction is not performed in real time during image formation, and only one process is performed. If a plurality of processes are tried to be performed in real time, for example, between sheets of image formation, it is difficult to select a process that can be executed, and a user cannot easily perform setting.
The present invention has been made in view of the above-described circumstances, and at least one object of the present invention is to provide an image forming device which enables a plurality of image analysis processes to be performed in real time, and an image forming method and an image forming system.